This invention concerns a control device for evaporators and similar vapor handling systems. One such use is as a seal in a small scale solvent recovery system of the type shown in U.S. Pat. No. 4,457,805.
In evaporators in general, and heated vapor handling systems in particular, seals have a primary function to limit the flow of vapors, gases, or liquids and to restrict them to a particular area or volume for purposes of process requirements, cost, efficiency, safety or other reasons. Many types of physical seals are known and are all prone to defects and failures due to physical abuse, chemical attack, and thermal over limiting, etc.
Because of these problems with physical seals, there is a need for an improved type of seal which obviates these concerns when dealing with vaporized liquids.